Last year we had Bokito making the headlines, a gorilla from Rotterdam zoo. Apparently he has several female admirers of the human variety, one of whom was warned several times that she should not be making such close eye contact with the animal - and she was there nearly every other day. So one day Bokito gets extremely annoyed, and manages to jump the fence - which was high enough according to the official standards - then he grabs the lady and drags her along for about 20 minutes, with the rest of the public fleeing and taking cover. The lady got badly injured, and had about a hundred bitemarks.
The animal was not shot dead, and I don't think the zoo was condemned for negligence. They have rebuilt the gorilla enclosure to make it Bokito-proof.